Viridius is the court composer of the Goreddi court at Lavondaville. He is ridden with gout and thus assigns many of his duties to his new assistant, Seraphina. He is romantically involved with his protégé, Lars.
Viridius worked with the talented musician Tertius, traveling with him. He met Linn and was astounded when Tertius confided to him that Linn was a saar. Viridius encouraged her to take a teaching position at St. Ida's.
Viridius became the court composer of the Goreddi court. When Princess Glisselda was a toddler, he wrote the Suite Infanta in her honor. When she grew older, he became her music tutor; Viridius had no patience with her, leading to a form of war between them. However, his gout worsened, forcing him to take on an assistant. Glisselda refused all of his candidates except for Seraphina, whom Viridius approved of and hired.
Ridden with gout, Viridius is unable to attend Prince Rufus's funeral. The next morning he leads choir practice for Comonot's visit and rebukes Seraphina for arriving late, reminding the crowd that music is the one thing dragons cannot do because they do not have souls. He and Seraphina run through a checklist of what still needs to be done—Viridius is displeased that they still have not finished auditions, which he wanted done a month ago—which reminds him that Seraphina has still not met Lars. He tells her to do so, and he also tells her that she must attend one of Princess Glisselda's evening soirees; when Seraphina refuses, he threatens to fire her if she does not.
Viridius is rather old-fashioned and cantankerous.
- Fantasias. These were the first of Viridius's music that Seraphina read, and they caused her to become a fan of his work.
- Suite Infanta, written for Glisselda when she was a toddler. Seraphina describes it: "a strange piece, all merriment on the surface with a hidden sharpness underneath, like a knife wrapped in ribbons"
When Glisselda was a toddler, Viridius wrote the Suite Infanta for her; Seraphina believes the song, which is pretty but with a lurking sharpness underneath, fits Glisselda well, demonstrating that Viridius very quickly understood Glisselda's character.
As her music tutor when she was older, Viridius had no patience with her and would make very frank, unflattering comparisons between Glisselda and various vegetables in regards to her musical skills. Glisselda retaliated with various pranks, infuriating Viridius, and as his gout worsened, Viridius decided that teaching Glisselda was too trying, raising his heartbeat and giving him palpitations.
Viridius considers Glisselda very capable, though not in music.